Optofluidics Inc. proposes to develop a near field optical chromatograph, the BioPrism, and apply it to the characterization of particle coating stability in nanomedicine. According to clinicaltrials.gov, about 10% of all clinical trials involv nanoparticles and the National Science Foundation has predicted that nearly half of future pharmaceuticals will have some nanotechnology component. Some of the prime motivations for moving to nanoparticle based drug formulations are the higher activity associated with larger relative surface areas and the ability to stably disperse inherently insoluble hydrophobic materials. Critical to enabling both these potentially revolutionary capabilities is the developmen of stable nanoparticle coatings. Failure to do so results in particle agglomeration, aggregation and ultimately nanotoxicity. As we describe in the proposal through a series of industry reports, quotes from top experts, and specific case studies, there is a distinct lack of instrumentation tha can rapidly assess nanoparticle coatings and the development of such a system could both reduce the time to market for new drugs and increase patient safety. The BioPrism method uses laser light to push particles along the surface of a waveguide and is based on technology licensed from Cornell University and further developed by Optofluidics. Briefly, the surface interaction between the particle and the waveguide affects particle mobility and residence time, enabling separation in the same way as adsorption chromatography. As we demonstrate in the proposal however the use of optical forces to drive the separation process enable a potential order of magnitude increase in size resolution over that possible with existing chromatography systems. This significantly finer resolution provides us with a potentially disruptive advantage, enabling the direct measurement of changes in particle coatings rather than relying on the observation of second order late stage effects, such as agglomeration, like existing instruments do. At the conclusion of this Phase II effort we will have developed a BioPrism cassette that is both validated by our industry partners and collaborators and compatible with our existing instrument product line thereby facilitating our path to market.